JFFS2 as transactional FS (in other words: how to be sure that data have been writtent correctly from userspace)

[Josh Boyer]

On Thu, 2007-03-08 at 13:22 +0000, David Woodhouse wrote:
> On Thu, 2007-03-08 at 14:12 +0100, Jörn Engel wrote:
> > Then you have your bug report.  Ignoring those was ok in 2001, but with
> > wbuf I would at least expect JFFS2 to return an error.
> 
> Not quite, because that's not what he was trying. He said he was using
> fsync().
> 
> I would hope that JFFS2 doesn't _have_ to return an error -- the VFS
> should do so if the filesystem doesn't support a given option. That
> doesn't seem to be the case though, so I agree that we should make JFFS2
> check for those two flags and refuse the operation (mount/open) for
> write-buffered flash.

Wait... why?  Rejecting mount -o sync seems sane, but why can't O_SYNC
support be handled?  If users want to open their files like that and it
causes JFFS2 to flush a bunch of padding out, well they asked for it.

josh